The hedgehog survey runs throughout the summer

The 2004 Mammals on Roads survey says the numbers of hedgehogs spotted per mile has fallen significantly.

In England as a whole, numbers along roads have fallen by more than 20% since the survey started in 2001. The east has seen the biggest decline.

Between July and September volunteers are asked to keep an eye out for mammals along Britain's roads.

'Alive and dead'

Jill Nelson, chief executive of the Mammals Trust UK (MTUK), which organises the survey, said: "It is of great concern to see that the decline in hedgehog numbers is continuing.

"However, we hope the public will react positively to this unfortunate news by choosing to assist us by taking part in this year's survey."

This year's survey runs to the end of September, and asks volunteers to record numbers of mammals they see, both alive and dead, on stretches of single carriageway roads on journeys of 20 miles or more.

Dr Paul Bright of Royal Holloway, University of London, who is responsible for the analysis of the survey's results, said: "Mammals on Roads is currently the only survey able to monitor hedgehog numbers on a national scale."